The use of various indwelling catheters, especially feeding devices, is well known in the medical art. Feeding tubes may be left in place within the body for a considerable period of time, often up to a year. This is possible due to the use of recent advancements in biocompatible materials, especially silicone indwelling devices which permit long term placement of a device without body rejection or tissue reaction.
Medical grade silicone devices are routinely used in gastrostomy feeding devices as well as other types of devices such as wound drains and infusion catheters. The silicone material has many biocompatibility advantages including the ability to remain soft and flexible for long periods of time within the body.
Feeding devices and catheters made from silicone are molded, extruded, and assembled such that the silicone material is very smooth and the surface finish has a very low coefficient of friction. The surface of the silicone catheter becomes very slippery especially when it is in contact with body fluids.
To prevent inward migration of the catheter, designers and manufactures have added external retention devices to their products. Silicone retention discs are manufactured in various sizes to stabilize catheters and are produced by such companies as Wilson-Cook.
Gastrostomy feeding devices are also available from C. R. Bard, Ross Laboratories, and Superior Biosystems (manufactured for Sandoz Nutrition Inc.) with pre-loaded retention discs already on the catheter.
Low profile gastrostomy ports of fixed lengths are also produced by these three manufacturers, and are available in various sizes and lengths with molded in external bolsters to prevent tube migration.
The problem with the retention discs is that they easily slide on the tubular shaft of the catheter and the catheter easily migrates inside the body.
If the gastrostomy devices has an inner balloon then the ballon can block internal body passageways and cause an obstruction if the retention disc fails. This is often the case.
To prevent disc slippage, pull ties have been added to the disc. However, the disc still often fails due to the smooth slippery outer surface of the catheter and the smooth inner surface of the molded retention disc.
The low profile gastrostomy devices from C. R. Bard, Ross, or Superior must be molded with fixed lengths which means extra devices to measure the lengths of patients' stoma tracts and the added inventory and expense of many different fixed lengths and sizes.
The low profile devices of Gauderer U.S. Pat. No. 4,863,438 and Russo U.S. Pat. No. 4,944,732 all show fixed lengths.
The low profile devices of Gauderer and Russo have many advantages, however, many hospitals do not use these devices because of the large inventory of different sizes and lengths required, and the frustration of doctors and nurses in selecting the right size. Even with all the sizes available, some patients cannot be fit with a low profile device because the correct length is not available.
Manufacturing and inventory costs of the low profile devices make them very expensive for most patients and hospitals.